US7571913B2 - Tracked bicycle - Google Patents

Abstract

A tracked vehicle includes a track assembly with a bogie assembly for riding on snow, mud, sand, etc. The track assembly includes a continuous track movably disposed about a drive wheel and a bogie wheel disposed rearward of the drive wheel. The drive wheel and bogie wheel are pivotally coupled to a rear fork. The rear fork is pivotally coupled to a frame of the tracked vehicle. A bias member biases the drive wheel and the bogie wheel towards the ground.

Description

PRIORITY CLAIM

Priority of U.S. Provisional Patent Application Ser. No. 60/762,386, filed on Jan. 25, 2006 is claimed; and is herein incorporated by reference.

This is a continuation-in-part of U.S. patent application Ser. No. 11/444,126, filed on filed May 30, 2006; which is a continuation of U.S. patent application Ser. No. 10/737,107, filed Dec. 15, 2003, now abandoned; which is a continuation-in-part of U.S. application Ser. No. 10/020,658, now U.S. Pat. No. 6,663,117, filed Oct. 29, 2001; all of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to tracked vehicles. More particularly, the present invention relates to a tracked bicycle for use on snow, sand, mud, etc.

2. Related Art

Mountain biking, off-road bicycling, and/or bicycling in and around nature have become popular sports or pastimes. Bikers or cyclists often enjoy riding in wilderness or natural environments, such as the woods, sand dunes, red-rocks, etc. Such environments can provide a welcome change from city or suburban environments. In addition, such environments can provide unique and challenging riding conditions, including steep uphill climbs, steep downhill descents, sharp curves, etc. Some wilderness or natural environments are provided with bike trails. Such trails can be simple paths in the dirt or sand, while others can be graded or covered with gravel, while still others may be paved. Another unique and challenging riding condition of the wilderness or natural environments is obstacles, such as larger rocks, fallen tree trunks, streams and rivers, mud, sand dunes, etc. These natural conditions provide additional enjoyment and challenge to the cycling experience.

Such bicycling or cycling is often dependent on weather conditions, or seasons. While some areas or locations allow for year-round riding, other areas can be limited to the spring, summer and fall months. For example, many popular riding areas are located in the mountains, where annual winter snowfall prohibits riding off-road or on non-maintained trails. In addition, it will be appreciated that most maintained roads are for motor vehicles, and that sharing a road with such motor vehicles in winter conditions can be extremely dangerous. Therefore, even the most ardent mountain bikers tend to store their bikes for the winter and opt for either in-door stationary bicycles, alternative winter sports such as snowshoeing or cross-country skiing, or simple waiting out the winter.

Some efforts have been made to continue mountain biking in the winter. For example, bicycles have been proposed with “fat” or wide tires to prevent sinking into the snow. Such bicycles have special, wide frames to accommodate the fat or wide tires. Thus, the rider must invest in another bicycle with this approach. As another example, standard mountain bikes have been proposed with special tires that have spikes or studs. Such tires tend to be thin enough to sink into the snow. As a further example, devices have been proposed with a seat disposed on front and rear skis. Such devices, however, are suitable only for coasting down a slope, and are not provided with any means of propulsion.

Various tracked, off-road, recreational vehicles have been proposed. Such vehicles have a continuous track, similar to tank tracks, as opposed to, or in addition to, wheels. While some tracks have been used for motor powered vehicles, such as all-terrain-vehicles (ATVs), it is not readily apparent how to adapt such tracks for use with human-powered vehicles, such as bicycles. Some tracks have been proposed for use with human-powered vehicles, but are cumbersome and awkward. Additionally, the tracks on such vehicles can accumulate snow, ice and debris, making them difficult, if not impossible, to move by human power.

SUMMARY OF THE INVENTION

It has been recognized that it would be advantageous to develop a human powered tracked vehicle capable of being realistically operated in conditions or environments such as snow, mud, sand, etc. In addition, it has been recognized that it would be advantageous to develop a tracked vehicle with improved traction and buoyancy with respect to the riding surface. In addition, it has been recognized that it would be advantageous to develop a tracked vehicle with a continuous track that can be operated in different environmental conditions, such as ice, snow, mud and hard surfaces.

The invention provides a tracked vehicle, including a frame having a seat. The tracked vehicle also has a front steering post and a handle bar. The front steering post and handle bar are attached to one another and pivotally coupled to the frame. A drive assembly is also coupled to the frame. The drive assembly includes a gear that is rotatably coupled to the frame, and a drive chain that is movably disposed around the gear. A rear fork is pivotally coupled to the frame and has a pair of spaced apart members pivoted at a front or proximal end to the frame. The spaced apart members extend upward to a biasing attachment and then rearward and downward to a drive wheel attachment and then rearward to a bogie wheel attachment. A drive wheel is rotatably attachable to the rear fork, and operatively attachable to the drive chain. A bogie wheel is also attached to the rear fork and is located rearward of, and spaced apart from, the drive wheel. A continuous track is movably disposed around the drive and bogie wheels. A bias member is operatively coupled between the frame and the rear fork and biases the drive wheel and bogie wheel towards the ground.

Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a standard bicycle with a kit having a track assembly and front ski in accordance with the present invention installed thereon to form a tracked vehicle in accordance with the present invention;

FIG. 2 is a top view of the track assembly ofFIG. 1;

FIG. 3 is a side view the track assembly ofFIG. 1 showing multiple positions of the track assembly;

FIG. 4 is a side view of the track assemble ofFIG. 3;

FIG. 5 is a perspective view of a bracket in accordance with the present invention for attaching the track assembly or a bogie wheel to the bicycle;

FIG. 6 is a perspective view of a ski post in accordance with the present invention for attaching a ski to a front fork of a bicycle;

FIG. 7 is a side view of a standard bicycle;

FIG. 8 is a side view of the standard bicycle ofFIG. 7 with a track assembly in accordance with the present invention installed thereon to form a tracked vehicle in accordance with the present invention;

FIG. 9 is a side view of the standard bicycle ofFIG. 7 with a ski assembly in accordance with the present invention installed thereon to form a skied vehicle in accordance with the present invention;

FIG. 10 is a perspective view a kit having a track assembly and front ski in accordance with the present invention shown on a standard bicycle (partially shown) to form a tracked vehicle in accordance with the present invention;

FIG. 11 is a side view of the track assembly ofFIG. 10;

FIGS. 12 and 13 are perspective views of the track assembly ofFIG. 10;

FIG. 14 is a side view of the kit shown inFIG. 10;

FIG. 15 is a side view of the track assembly ofFIG. 10;

FIG. 16 is a top view of the track assembly ofFIG. 10;

FIG. 17 is a rear view of the track assembly ofFIG. 10;

FIG. 18 is a detailed cross-sectional view of the track ofFIG. 10;

FIG. 19 is a side view of a tracked vehicle in accordance with another embodiment of the present invention;

FIG. 20 is a rear perspective view of the tracked vehicle ofFIG. 19;

FIG. 21 is a partial perspective view of a continuous track in accordance with the present invention;

FIG. 22 is a side view of a tracked vehicle in accordance with another embodiment of the present invention;

FIG. 23 is a perspective view of the tracked vehicle ofFIG. 22;

FIG. 24 is a partial perspective view of a drive wheel and a continuous track on the tracked vehicle ofFIG. 22;

FIG. 25 is a cut-away view of the drive wheel and continuous track ofFIG. 22;

FIG. 26 is a side view of a tensioning device tensioning a continuous track on the tracked vehicle ofFIG. 22; and

FIG. 27 is a perspective view of the tensioning device ofFIG. 24.

DETAILED DESCRIPTION

Reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

As illustrated inFIG. 1, akit10 in accordance with the present invention is shown installed on a standard bicycle14 (FIG. 7) to convert it into a tracked cycle or trackedvehicle18. Mountain bikes, mountain biking, bicycles, cycling and human-powered vehicles are examples of fields that may benefit from the use of such akit10 or trackedvehicle18. Thekit10 can include atrack assembly22 and aski assembly26 that advantageously can be installed on the standard bicycle14 (FIG. 7) to create a trackedvehicle18 with improved traction and/or buoyancy on ariding surface30, such as snow, mud, sand, etc. Thus, the performance or function of a standard bicycle or human powered vehicle can be improved for certain riding conditions, enhancing or extending the riding experience. In addition, thekit10 allows a user or rider to use a single vehicle or bicycle for both wheeled and tracked applications.

While thekit10 of the present invention is shown and configured for use with a standard bicycle, it is of course understood that the kit can be configured for use with other types of human-powered vehicles, or bicycles with different configurations, such as recumbent bicycles or different frame configurations. In addition, it is understood that while the kit is shown and configured for use with human-powered vehicles, it can be configured for used with powered or motor vehicles. Furthermore, it is understood that while the kit, or track and ski assemblies, are shown as accessories for being removably coupled to a standard bicycle, the track and/or ski assemblies can be permanently or integrally provided on a vehicle to form a dedicated tracked vehicle.

Referring toFIGS. 1 and 7, thebicycle14 or trackedvehicle18 preferably has aframe34 with aseat36 to support a rider and a rear fork (or rear stays)38. Therear fork38 can have arear axle location40 where a rear wheel41 (FIG. 7) can be rotatably coupled to theframe34. Preferably, afront fork42 is pivotally coupled to theframe34, and attached to ahandlebar44 for a user to grasp and pivot thefront fork42. Thefront fork42 also can have afront axle location46 where a front wheel48 (FIG. 7) can be rotatably coupled to thefront fork42 orframe34. Adrive assembly50 can be coupled to theframe34, and can include apeddle gear52 rotatably coupled to theframe34, peddles54 attached to thepeddle gear52 to allow a rider to rotate the peddle gear, and adrive chain56 operative disposed around thepeddle gear52 to transfer the rotation and/or force of the peddles gear.

Referring toFIGS. 1 and 2, thetrack assembly22 includes acontinuous track60 movably disposed around a pair of opposite, spaced-apart wheels, including adrive wheel64 and abogie wheel68. Thedrive wheel64 turns or drives thetrack60, while thebogie wheel68 allows anelongated portion72 of thetrack60 to contact the ridingsurface30. Theelongated portion72 of thetrack60 increases the surface area of thetrack60 contacting the ridingsurface30 to improve traction and buoyancy. As discussed in greater detail below, thebogie wheel68 advantageously is flexibly and resiliently coupled to theframe34 ordrive wheel64, and biased towards the ridingsurface30, to improve traction. Preferably, thetrack assembly22 is removably coupled to theframe34 so that the track assembly can be selectively coupled and uncoupled from theframe34. Thus, thetrack assembly22 can be selectively coupled to theframe34 to convert the standard bicycle14 (FIG. 7) into the tracked cycle orvehicle18.

Thetrack60 can be formed of a flexible material so that it can travel around the drive andbogie wheels64 and68. Protrusions can extend outwardly from thetrack60 to increase traction or prevent slippage of the track with respect to the ridingsurface30. Thetrack60 can be an integral, continuous loop, or can be separable. Thetrack60 preferably has a width sized to extend substantially across the available width between therear fork38. Thus, thetrack60 can be utilized with a standard bicycle14 (FIG. 7), and maximize surface area and buoyancy on the ridingsurface30, such as snow.

Thedrive wheel64 is rotatably coupled to theframe34 orrear fork38. Preferably, thedrive wheel64 is removably coupled to theframe34 orrear fork38 so thedrive wheel64 can be selectively coupled and uncoupled from the frame. In addition, thedrive wheel64 preferably is coupled at therear axle location40 of therear fork38, or has a drive axle coupled at the rear axle location, much like a typical rear wheel. Thedrive wheel64 can have one or more drive gears74 (FIG. 2) that are operatively engaged by thedrive chain56 such that a rider peddling thepeddles54 drives thedrive wheel64 through thepeddle gear52 anddrive chain56. Coupling thedrive wheel64 at therear axle location40 advantageously allows thedrive assembly50 of a standard bicycle to also drive thedrive wheel64.

Thebogie wheel68 preferably is disposed rearward of, and spaced-apart from, thedrive wheel64. One or more flexible andresilient arms80 advantageously couple thebogie wheel68 to theframe34. Preferably, a pair ofarms80 is coupled to and between theframe34 and thebogie wheel68, each one on an opposite side of the bogie wheel. Thearms80 have a first end attached to theframe34, and a second end coupled to thebogie wheel68. Thus, thebogie wheel68 is attached to theframe34 in a cantilever configuration. Thebogie wheel68 andarms80 form a bogie assembly orapparatus84 for use with thetrack60 ortrack assembly22 of the trackedvehicle18.

Referring toFIG. 3, thearms80 are compliant and resilient to allow thebogie wheel68 to move or pivot with respect to theframe34. Thus, thebogie wheel68 can move upward or downward in response to the ridingsurface30, or riding conditions. For example, thebogie wheel68 andtrack60 can displace upwardly, indicated at84 by dashed lines. In addition, thearms80 exert a force against thebogie wheel68, and thus thetrack60, to force thetrack60 against the ridingsurface30 to improve traction. For example, in softer snow, thebogie wheel68 andtrack60 can deflect downwardly, indicated at88 by dashed lines, to maintain contact with the snow as it compresses. Thearms80 bend or deflect as thebogie wheel68 moves or pivots.

Referring toFIG. 4, thearms80 can be pre-loaded to exert a predetermined amount of force against thebogie wheel64. Thus, thetrack60 exerts a predetermined amount of force against the ridingsurface30. Thearms80 preferably exert a force when thetrack assembly22 orbogie wheel64 is in a normal configuration or position, such as when thetrack assembly22, orlower portion72 thereof, and the ski align on a flat riding surface. Thus, thearms80 can be bent to exert a force in the normal configuration. It has been determined that the arms preferably exert approximately 5-25 pounds of force for approximately 1-3 inches of deflection.

Thearms80 preferably are formed of a flexible and resilient material. Thus, thearms80 form springs or bows, attaching thebogie wheel64 to theframe34. In one aspect, thearms80 are composite arms formed of a composite material, such as pultruded fiberglass. For example, thecompliant arms80 may be formed of 1.25″×0.25″ bars of pultruded fiberglass. The pultruded fiberglass can include glass fibers densely packed and embedded in a polyester resin. In one aspect, the material of thearms80 has a modulus of elasticity between approximately 3 and 6 Msi; more preferably between approximately 3 and 5 Msi; and most preferably between approximately 3 and 4 Msi. It is of course understood that such specifications are dependent on the specific dimensions of the arm.

In addition to thetrack assembly22, thekit10 also preferably includes aski assembly26. Theski assembly26 preferably is removably coupled to thefront fork42. Theski assembly26 includes aski100 coupled to thefront fork42. Anelongated ski post104 can be removably attachable to thefront fork42, and extend to aconnector108 on a lower end thereof to pivotally couple to theski100. Theski post104 can include alower mounting bracket112 attachable to thefront axle location46 of thefront fork42, and anupper mounting bracket114 attachable to thefront fork42, or to a brake location of the front fork. Theski post104 allows the front fork of a standard bicycle to be used with theski100.

Referring toFIGS. 1 and 5, thetrack assembly22 can be attached to the frame in any appropriate manner. As an example, a universal bracket can be used which is configured to removably attach thetrack assembly22 to a number of different frame configurations, or rear fork configurations. One ormore frame brackets120 can have a vertically oriented portion to be disposed adjacent therear fork38. One or more braces, such as upper andlower braces124 and126, can be adjustably attached to theframe bracket120 to clamp therear fork38 between thebraces124 and126 and thebracket120. Theupper brace124 can clamp an upper member of therear fork38 to thebracket120, while thelower brace126 can clamp a lower member of therear fork38 to thebracket120. As shown, theframe bracket120, or vertically oriented portion thereof, can be elongated to extend across therear fork38 of different frame configurations. In addition, thebraces124 and126 can be selectively secured along thebracket120, such as along a plurality of holes, to adjust for different frame configurations. A hole130 can be formed in thebracket120 to receive the axle of thedrive wheel64.

Thearms80 can be attached directly to thebrackets120, thus coupling thebogie wheel68 to thebrackets120 and theframe34. The first ends of thearms80 can be attached to a horizontal portion of thebrackets120, such as by clamping between thebracket120 and aclamp plate134.

Thedrive wheel64 can be attached directly to therear fork38 of theframe34. Preferably, thedrive wheel64 is located at therear axle location40, similar to the standard rear wheel41 (FIG. 7), so that thedrive wheel64 can be coupled to thedrive chain56 without further modification of thedrive assembly50. Alternatively, thedrive wheel64 can be attached to thebracket120 so that theentire track assembly22 can be attached and removed as a unit.

Referring toFIGS. 1 and 4, thetrack assembly22 or thebogie assembly84 can include a tensioner ortension mechanism140 to maintain tension on thetrack60 between the drive andbogie wheels64 and68. Thetensioner140 can movably couple thebogie wheel68 to thearms80. Thus, thetensioner140 can move thebogie wheel68 away from thedrive wheel64 as thebogie wheel68 pivots with respect to the frame. It will be appreciated that as thebogie wheel68 pivots with respect to the frame, thearms80 cause thebogie wheel68 to move slightly closer to the frame, thus decreasing tension on thetrack60. Thetensioner140 moves thebogie wheel68 away from the frame to maintain tension.

For example, thetensioner140 can include abogie bracket144 attached to the second end of thearm80 opposite the frame or frame bracket. Apivot bar148 has a first end pivotally attached to thebogie bracket144 so that the pivot bar pivots with respect to thebogie bracket144 towards and away from the bogie bracket, and pivots towards and away from the frame. Thebogie wheel68 is coupled to the second end of thepivot bar148 so that thebogie wheel68 is movable with respect to thebogie bracket144, and thus thearms80. Thebogie wheel68 is biased away from the frame. Aspring152 is coupled between thebogie bracket144 and thepivot bar148. The spring can extend from a protrusion on the bogie bracket, which extends away from the frame, and the second end of the pivot bar. Thus, thespring152 pulls thepivot bar148 and thebogie wheel68 away from the frame and tensions thetrack60.

The trackedvehicle18 preferably has two or more configurations, including a wheeled configuration, as shown inFIG. 7, and a tracked configuration, as shown inFIG. 1. Referring toFIG. 7, the vehicle can be astandard bicycle14. Therear wheel41 is coupled to therear fork38 at therear axle location40, and coupled to thedrive chain56 of thedrive assembly50. In addition, thefront wheel48 preferably is coupled to thefront fork42 at thefront axle location46.

Referring toFIG. 1, in the tracked configuration, thetrack assembly22 is coupled to theframe34 orrear fork38, preferably at therear wheel location40. Thedrive chain56 of thedrive assembly50 is operatively coupled to drivewheel46. In addition, theski100 orski assembly26 preferably is coupled to thefront fork42.

It will be appreciated that the other configurations are possible. For example, referring toFIG. 8, the trackedassembly22 can be coupled to therear fork38, and thefront wheel48 can be coupled to thefront fork42. Such a configuration can be useful for riding in mud or sand. As another example, referring toFIG. 9, theski assembly26 can be coupled to thefront fork42, and therear wheel41 can be coupled to therear fork38. Such a configuration can be useful in other riding conditions. Thus, thekit10 of the present invention advantageously is capable of providing multiple different vehicle configurations, as shown in FIGS.1 and7-9.

It will be appreciated that the standard brakes associated with the standard bicycle14 (FIG. 7) can be removed or may be inoperable for the trackedvehicle18 or the tracked configuration. Thus, referring toFIG. 2, thetrack assembly22 can include adisk brake160 attached to thedrive wheel64 to provide braking. The trackedvehicle18 can utilize a hydraulic brake which engages thedisk brake160.

Referring toFIGS. 1 and 2, thedrive wheel64 can have a plurality of teeth orprotrusions170 formed thereon which mate with a plurality ofapertures174 formed in thetrack60. The teeth andapertures170 and174 resist slipping between thedrive wheel64 andtrack60. Alternatively, teeth can be formed on the track to mate with indentations in the drive wheel. Similar teeth can be formed in thebogie wheel68. Theteeth170 preferably have an involute profile in which the profile of theteeth170 curve inwardly near the tip. The involute profile of theteeth170 advantageously allows thetrack60 orapertures174 to follow the profile of theteeth170, and thus promote proper seating between thetrack60 and theteeth170. In addition, theteeth170 andapertures174 laterally maintain thetrack60 on thewheels64 and68.

While aseparate drive wheel64 has been described, it will be appreciated that therear wheel41 of thestandard bicycle14 can be configured as thedrive wheel64. In addition, thedrive wheel64 can have a plurality of different sized gears, similar to therear wheel41. Furthermore, either of the drive orbogie wheels64 and68 can have any appropriate configuration, such as multiple wire spokes extending from the axle to the rim, a few composite spokes, a single, solid disc spoke, etc.

A method for converting the standard bicycle14 (FIG. 7) into a tracked cycle18 (FIG. 1) includes removing the standard rear wheel41 (FIG. 7) from therear fork38, and from thedrive chain56. The standard rear brakes (not shown) also may be removed from therear fork38. Thetrack assembly22 is coupled to theframe34 orrear fork38. Thedrive wheel64 is coupled to therear fork38, preferably at therear axle location40, and operatively coupled to thedrive chain56, such as by looping thedrive chain56 around one of the gears on thedrive wheel64. Thedrive wheel64 can have an axle that is secured to therear fork38 with a threaded rod and nuts, similar to therear wheel41. Preferably, thetrack60 is looped about thedrive wheel64 prior to attachment to therear fork38. Alternatively, if the track is separable, the track can be looped around the wheels later. Thearms80 are secured to therear fork38 orframe34. For example, theframe bracket120 can be positioned adjacent therear fork38, and the upper andlower braces124 and126 (FIG. 5) located adjacent respective upper and lower portions of therear fork38. The upper andlower braces124 and126 can be secured to theframe bracket120 to secure therear fork38 therebetween.

Thetrack60 can be looped about both the drive andbogie wheels64 and68. Theteeth170 are mated with the apertures174 (FIG. 2) in thetrack60. Thetensioner140 can be held or disengaged while thetrack60 is looped about thewheels64 and68. After thetrack60 is positioned, thetensioner140 can be released or engaged to tension the track.

A hydraulic brake (not shown) can be attached to theframe34 orhandlebars44 to engage the disc brake160 (FIG. 2) on thedrive wheel64.

In addition, the standard front wheel48 (FIG. 7) can be removed from thefront fork42 and replaced with theski assembly26. The standard front brake (not shown) also can be removed. Theski100 can be coupled to thefront fork42 with theski post104. Thelower mounting bracket112 can be attached to thefront axle location46 similar to the front wheel, or with a threaded rod and nuts. Theupper mounting bracket114 can be attached to thefront fork42 above thelower mounting bracket112, such as to the front brake location.

It will be appreciated that thekit10 ortrack assembly22 allows a standard bicycle14 (FIG. 7) to be quickly and easily converted into a trackedvehicle18. Thekit10 ortrack assembly22 allows the user or rider to utilize thesame frame34 and other components for both the wheeled cycle or configuration, and the tracked cycle or configuration, thus saving the cost of having purchase two different vehicles. As stated above, thetrack assembly22 can be provided on theframe34 for a dedicated trackedvehicle18.

In addition, thebogie wheel68 and compliant andresilient arms80 facilitate use of thetrack assembly22 or trackedvehicle18 on the ridingsurface30, such as snow, mud, sand, etc. Thearms80 exert a force against thebogie wheel68 to maintain thetrack60 orflat portion72 thereof against the ridingsurface30.

As illustrated inFIGS. 10-15, anotherkit210 in accordance with the present invention is shown installed on a standard bicycle convert it into a tracked cycle or trackedvehicle218. Thekit210 and trackedvehicle218 are similar in many respects to those described above, and thus much of the above description applies to the present embodiment and will not be repeated. The bicycle214 can be similar to that described above (FIG. 7) or can have a similar configuration as known in the art with a frame234 (partially shown), arear fork38 and afront fork42. Thekit210 can include atrack assembly222 and aski assembly226 that advantageously can be installed on the standard bicycle to create the trackedvehicle218 with improved traction and/or buoyancy on a riding surface, such as snow, mud, sand, etc. Thekit210 allows a user or rider to use a single vehicle or bicycle for both wheeled and tracked applications.

Thetrack assembly222 includes acontinuous track260 movably disposed around a pair of opposite, spaced-apart wheels, including adrive wheel264 and abogie wheel268. Thedrive wheel264 can be formed by therear wheel41 of the bicycle, such as the rim of the rear wheel with the tire and tube removed. Thedrive wheel264 turns or drives thetrack260, while thebogie wheel268 allows an elongated portion272 (FIG. 11) of thetrack260 to contact the riding surface. Theelongated portion272 of thetrack260 increases the surface area of thetrack260 contacting the riding surface to improve traction and buoyancy. Thebogie wheel268 is more rigidly coupled to theframe234, therear fork38, or drivewheel264 than that described above. In addition, thetrack assembly222 can be removably coupled to theframe234,rear fork38 and/orrear wheel41 so that thetrack assembly222 can be selectively coupled and uncoupled from the bicycle214frame234,rear fork38, and/orrear wheel41. Thus, thetrack assembly222 can be selectively coupled to the frame to convert the standard bicycle214 into the tracked cycle orvehicle218.

Thetrack260 can include an interior protrusion278 (FIG. 18) with a v-shaped cross-sectional shape. Theprotrusion278 can be receivable in the rim of the drive wheel, and in thebogie wheel268. The protrusion assists in maintaining the track on the wheels. In addition, thetrack260 can include an exterior tread or the like as described above.

Thebogie wheel268 can be disposed rearward of, and spaced-apart from, thedrive wheel264. One ormore arms280 can couple thebogie wheel268 to theframe234. A pair ofarms280 can be coupled to and between theframe234 and thebogie wheel268, each one on an opposite side of the bogie wheel. Thearms280 have a first end attached to theframe234 orrear fork38, and a second end coupled to thebogie wheel268. Thus, thebogie wheel268 is attached to theframe234 in a cantilever configuration. Thebogie wheel268 andarms280 form a bogie assembly or apparatus for use with thetrack260 ortrack assembly222 of the trackedvehicle218. The bogie wheel can have an axel slidably received in slots on the second ends of the arms and secured therein. A threaded fastener can extend from the axel of the bogie wheel and can be engagable by a nut or the like so that rotating the nut slides the axel within the slot to adjust the position the bogie wheel and tension the track. Alternatively, the axel of the bogie wheel can be threaded to receive a nut so that the arm is sandwiched between the nut and inner axel. In addition, the first ends of the arms can be selectively slidably with respect to the frame or rear fork to tension the track.

Thearms280 are more rigid than those described above. The arms can include a material and a configuration that is more rigid, while still allowing limited pivotal potion of the bogie wheel. Thearms280 can be formed of a rigid material, such as metal, and can have a plate or sheet like configuration. Thearms280 themselves can extend rearward in a more horizontal orientation, while the plate or sheet like configuration can be oriented vertically. Thearms280 can have a curvature in a substantially horizontal plane, or bends282 oriented vertically on the plate or sheet. Thearms280 can have three sections separated by thebends282, including a mountingsection280a, a transition orextension section280b, and abogie section280c, as shown inFIG. 16. The mountingsection280acan be attached to theframe234 orrear forks38, and thus can extend or flare outwardly from a front to a rear direction in order to match or mate with therear forks38. The transition orextension section280bcan extend between the mounting andbogie sections280aand280c, and can extend of flare back inwardly from a front to a rear direction. Thebogie section280ccan extend from the transition orextension section280band attach to thebogie wheel268, and can be straight or parallel along thebogie wheel268. Thus, thearms280 or transition orextension section280bcurves or extends inwardly.

The curvature or bends282 can allow the arms to bend of flex vertically, and thus allow thebogie wheel268 to move or pivot vertically with respect to the frame while the rigidity of the material of the arms tends to maintain the configuration and position of the bogie wheel. Thus, the curvature or bends allow thearms280 to have a degree of compliance or resiliency. Thus, thebogie wheel268 can move upward or downward in response to the riding surface, or riding conditions. For example, thebogie wheel268 and track260 can displace upwardly. In addition, thearms280 can exert a force against thebogie wheel268, and thus thetrack260, to force thetrack260 against the riding surface to improve traction. The curves or bends in thearms280 can allow the arms or portion thereof to bend or deflect inwardly or outwardly as the arms bend or deflect downwardly or upwardly. Thus, the material of the arms provides more rigidity, while the configuration or shape of the arms allows for limited movement.

An intermediate arm support284 (FIG. 13) can extend between and interconnect the pair ofarms280. Theintermediate arm support284 can be positioned between thedrive wheel264 and thebogie wheel268. Anintermediate track support286 can be disposed between thedrive wheel264 and thebogie wheel268. Theintermediate track support286 can engage a portion of the track272 (FIG. 11) extending between thedrive wheel264 and thebogie wheel268. Theintermediate track support286 can extend from theintermediate arm support284, and can maintain the track against the riding surface. In addition, theintermediate track support286 can include aleading edge288 and anangled surface290 angled at an acute angle with respect to the track. Theleading edge288 andangled surface290 can act to displace or scrape snow, mud and other debris from the interior of thetrack260, and resist the snow and the like from entering between thetrack260 andbogie wheel268. It has been found that snow and the like can get between thetrack260 andbogie wheel268 and interfere with performance or cause the track to come off the bogie wheel. Furthermore, theintermediate track support286 can include a slot292 (FIG. 18) with a v-shaped cross-sectional shape to receive theprotrusion278 of the track.

A pair of tabs can extend inwardly from the first end orattachment section280aof eacharm280 to engage theframe234 and transfer force from the arms to the frame. The tabs can include a forward andupper tab294 and a rearward andlower tab296. The forward andupper tab294 can be positioned at a forward and higher position, while the rearward andlower tab296 can be positioned at a rearward and lower position. A portion of theframe234, orrear forks38, can be received between the tabs. A top of the frame, or portion of theforks38, can be engaged by the forward andupper tab294, while a bottom of the frame, or portion of theforks38, can be engaged by the rearward andlower tab296.

Thearms280 orattachments sections280acan be attached to theframe234 orrear forks38 in any appropriate manner. For example,apertures298 can be formed in thearms280 to receive fasteners, such as bolts. A u-bolt can extend around a portion of therear forks38 and through theapertures298. Nuts can be threaded onto the ends of the u-bolt to secure the arms to the frame or rear fork. As another example, a mounting plate can be disposed on the inside of the rear forks and coupled to the arms by bolts, such that the rear forks are sandwiched between an arm on the outside and a mounting plate on the inside.

Thearms280 orattachment section280acan have a height sized to extend across the entirerear fork38, or across both upper and lower members of the rear fork. In addition, theattachment section280aof thearms280 can have a length to extend substantially along a length of the rear fork. Thus, thearms290 orattachment section280acan abut to a substantial portion of therear fork38 for stability.

The trackedvehicle218 can have two or more configurations, similar to those described above, including a wheeled configuration (FIG. 7) and a tracked configuration. In the wheeled configuration, the vehicle can be configured as a standard bicycle with therear wheel41 coupled to therear fork38 at therear axle location40, and coupled to the drive chain of thedrive assembly50. In addition, the front wheel can be coupled to thefront fork42 at the front axle location.

In the tracked configuration, thetrack assembly222 is coupled to theframe234 orrear fork38. Thetrack260 can be operatively coupled to or disposed around thedrive wheel264. Thedrive wheel264 can be therear wheel41 with the tire and rim removed. In addition, theski300 orski assembly226 can be coupled to thefront fork42.

A method for converting the standard bicycle into a trackedcycle218 includes removing the standardrear wheel41 from therear fork38, and from the drive chain. Thetrack assembly222 is coupled to theframe234 orrear fork38. The tire and tube can be removed from therear wheel41 to form thedrive wheel264. Thetrack260 can be looped around thedrive wheel264 to form the track assembly. Thedrive wheel264 is coupled to therear fork38, at therear axle location40, and operatively coupled to the drive chain. Thearms280 are secured to therear fork38 orframe234. In addition, the standard front wheel can be removed from thefront fork42 and replaced with theski assembly226. Theski300 can be coupled to thefront fork42.

As illustrated inFIGS. 19-20, another tracked bicycle or trackedvehicle500 in accordance with the present invention is shown for use on snow, ice, or muddy terrain. The trackedvehicle500 is similar in many respects to those described above, and thus much of the above description applies to the present embodiment. Additionally, the trackedvehicle500 is similar to the tracked vehicles described in U.S. patent application Ser. No. 10/737,107, filed Dec. 15, 2003, which is a continuation in part of U.S. Pat. No. 6,663,117, filed Oct. 29, 2001, as U.S. patent application Ser. No. 10/020,658, which are herein incorporated by reference in their entirety for all purposes.

The trackedvehicle500 can have aframe534 with aseat536 and arear fork538. The tracked vehicle can also have afront steering post542 and ahandlebar544. Thefront steering post542 and thehandle bar544 can be attached to one another and can pivotally together with respect to theframe534.

The tracked vehicle can also have adrive assembly550 coupled to theframe534. The drive assembly can include agear552 that can be rotatably coupled to the frame. Adrive chain556 can be movably disposed around thegear552. Adrive wheel564 can be rotatably attachable to the rear fork of the frame and operatively attachable to thedrive chain556. Thedrive wheel564 can be pivotally and fixedly attached to theframe534 to allow thedrive wheel564 to rotate without displacing relative to theframe534. Thus, in use thegear552 can be rotated which in turn moves thedrive chain556 which rotates thedrive wheel564. In one aspect, amotor700 can be associated with thegear552 to rotate thegear552 and drive thedrive chain556. In another aspect,pedals710 can be associated with thegear552 to rotate thegear552 and drive thedrive chain556.

Abogie wheel568 can be located rearward of, and spaced apart from, thedrive wheel564. At least onepivot arm570 can pivotally couple thebogie wheel568 to therear fork538. Thus, thebogie wheel568 can pivot with respect to therear fork538 so that in use as the trackedvehicle500 moves over uneven terrain, thebogie wheel568 will pivot up and down with respect to theframe538 thereby providing greater contact of the track with the terrain. In one aspect, pivotarms570, or a pair of pivot arms, can be disposed on each side of the drive wheel and the bogie wheel.

Referring toFIGS. 19-21, acontinuous track560 can be movably disposed around thedrive wheel564 and thebogie wheel568. Thetrack560 can have aninternal side562 and anexternal side566. Theinternal side562 can engage and be moved by thedrive wheel564 andbogie wheel568. Theexternal side566 can engage the ground and can provide force against the ground to move the trackedvehicle500. Theinternal side562 can haveprotrusions562athat can interact with thedrive wheel564 to move thetrack560. Theprotrusions562acan also interact with and rotate thebogie wheel568. Theexternal side566 can also haveprotrusions566a, or tread, that can engage the ground and provide additional forces for moving the trackedvehicle500.

Theprotrusions562aon theinternal side562 of thetrack560 can have a profile with interior v-shaped notches562bbetween theprotrusions562a. The v-shaped notches562bcan allow theprotrusions562ato pivot towards one another in use. Thus, as thetrack560 rotates around thedrive wheel564 and thebogie wheel568, theprotrusions562acan pivot toward and away from one another.

It will be appreciated that snow and ice can build up on theinternal side562 of thetrack560 and can interfere with the engagement of thetrack560 by the drive andbogie wheels564 and568. Advantageously, the pivoting of theprotrusions562acloses the v-shaped notches562bthereby effectively changing the shape and size of theinternal side562 of thetrack560, which can force ice and snow out of theinternal side562 of thetrack560. Thus, the v-shaped notches562bcan be sized and shaped to expel snow and ice from the continuous track as the protrusions pivot towards one another in use.

Abias member576 can be operatively coupled to the at least onepivot arm570. Thebias member576 can bias thebogie wheel568 towards the ground. It will be appreciated that biasing thebogie wheel568 to the ground will maintain greater surface area contact between thecontinuous track560 and the ground. Thus, in use, thebogie wheel568 can pivot up and down with respect to the frame as the trackedvehicle500 moves over uneven terrain, but thebogie wheel568 can be biased to a downward position so as to maintain maximum surface area contact between thetrack560 and the ground.

Thebias member576 can bias thebogie wheel568 by at least onelever arm572. The at least onelever arm572 can be rigidly coupled to the at least onepivot arm570 and can extend away from, and transverse to the at least onepivot arm570. Thus, thebias member576 can be positioned between the at least onelever arm572 and theframe538. It will be appreciated that thelever arm572 can act as a moment-arm force-multiplier between thebias member576 and thebogie wheel568 and thus, asmaller bias member576 can be used to bias thebogie wheel568 than if thebias member576 were located adjacent thebogie wheel568. Advantageously, asmaller bias member576 results in less weight on the trackedvehicle500. In one aspect, lever arms, or a pair of lever arms, can be disposed on each side of the drive wheel and can couple to the pair of pivot arms.

The trackedvehicle500 can also have afront ski assembly526. Theski assembly526 can be coupled to thefront steering post542. Theski assembly526 can include aski600 coupled to aski support602. Theski support602 can be pivotally attached to thefront steering post542, and can extend to aconnector608 on a lower end thereof to pivotally couple to theski600.

Thefront ski assembly526 can also have a ski shock absorber610. The ski shock absorber can be pivotally coupled between thefront steering post542 and theski support602. The ski shock absorber610 can absorb applied loads from theski support602 and minimize the transfer of forces between theski support602 and thefront steering post542. Thefront steering post542, theski support602, and the ski shock absorber610 can define a three bar linkage that positions the ski shock absorber610 to absorb loading from theski support602 and minimize the transference of loads from theski support602 to the front steering post610.

In one aspect, thefront steering post542 can curve in a smooth continuous curve rearward toward thedrive wheel564 of the trackedvehicle500. Additionally, theski support602 can be pivotally coupled at the rearward lowermost portion of thefront steering post542 and can curve forward in a smooth continuous curve toward theski600. The ski shock absorber610 can be coupled between the rearward curve of thefront steering post542 and the forward curve of theski support602, thereby forming a substantially triangular three bar linkage between thefront steering post542, theski support602, and the ski shock absorber610. Advantageously, the substantially triangular three bar linkage minimizes the loads transferred from theski600 to thefront steering post542.

Additional figures of the trackedvehicle500 described inFIGS. 19-21 can be found in Appendix A which includes additional embodiments and enabling information and is incorporated by reference in its entirety for all purposes herein.

As illustrated inFIGS. 22-23, another tracked bicycle or trackedvehicle800 in accordance with the present invention is shown for use on snow, ice, or muddy terrain. The trackedvehicle800 is similar in many respects to those described above, and thus much of the above description applies to the present embodiment. Additionally, the trackedvehicle800 is similar to the tracked vehicles described in U.S. patent application Ser. No. 10/737,107, filed Dec. 15, 2003, which is a continuation in part of U.S. Pat. No. 6,663,117, filed Oct. 29, 2001, as U.S. patent application Ser. No. 10/020,658, which are herein incorporated by reference in their entirety for all purposes.

The trackedvehicle800 can have aframe834 with aseat836. The tracked vehicle can also have afront steering post842 and ahandlebar844. Thefront steering post842 and thehandle bar844 can be attached to one another and can pivotally together with respect to theframe834.

The tracked vehicle can also have adrive assembly850 coupled to theframe834. The drive assembly can include agear852 that can be rotatably coupled to the frame. Adrive chain856 can be movably disposed around thegear852.

Arear fork900 can be pivotally coupled to theframe834. Therear fork900 can pivot at, or substantially at, thegear852 of thedrive assembly850. Thus, the rear fork can pivot without disrupting the chain. As shown inFIG. 23, therear fork900 can have a pair of spaced apartmembers910 and920 that can be pivotally attached at a front orproximal end912 and922, respectively, to theframe834. The spaced apartmembers910 and920 can extend upward to abias member attachment930. The spaced apart members can extend from thebias member attachment930 rearward and downward to adrive wheel attachment932 and from thedrive wheel attachment932 rearward to abogie wheel attachment934 near a distal orback end914 and924 respectively, of therear fork900.

The spaced apartmembers910 and920 of therear fork900 can have a smooth curvilinear profile between thefront ends912 and922 and the back ends914 and924. Advantageously the smooth curvilinear profile can reduce stress concentration points in therear fork900 and minimize transferring forces from therear fork900 to theframe834, thereby making a smoother more comfortable ride for the vehicle rider.

Adrive wheel864 can be rotatably attachable to therear fork900 and operatively attachable to thedrive chain856. Thedrive wheel864 can be pivotally and fixedly attached to therear fork900 to allow thedrive wheel864 to rotate without displacing relative to therear fork900. Thus, in use thegear852 can be rotated which in turn moves thedrive chain856 which rotates thedrive wheel864. In one aspect, amotor980 can be associated with thegear852 to rotate thegear852 and drive thedrive chain856. In another aspect,pedals984 can be associated with thegear852 to rotate thegear852 and drive thedrive chain856. In yet another aspect, as illustrated inFIG. 22, both a motor and pedals can be associated with thegear852, and the rider can selectively operate either themotor980 or thepedals984 to drive thechain856.

Abogie wheel868 can be located rearward of, and spaced apart from, thedrive wheel864. Thebogie wheel868 can be pivotally and fixedly attached to therear fork900 to allow thebogie wheel868 to rotate without displacing relative to therear fork900 or the spaced apart location of the bogie wheel with respect to thedrive wheel864. Thus, thebogie wheel868 and thedrive wheel864 can pivot with therear fork900 in relation to theframe834. In this way, as the trackedvehicle800 moves over uneven terrain, thebogie wheel868 and drivewheel868 can pivot up and down with respect to the frame838.

Acontinuous track860 can be movably disposed around thedrive wheel864 and thebogie wheel868, as shown inFIG. 22. Thetrack860 can have aninternal side862 and an external side866. Theinternal side862 can engage and be moved by thedrive wheel864 andbogie wheel868. The external side866 can engage the ground and can provide force against the ground to move the trackedvehicle800.

Referring toFIGS. 24-25, thecontinuous track860 can also include a plurality oftread segments890 that can be pivotally linked with one another to form a continuous flexible track. Each of the plurality oftread segments890 can have anaperture892 so that the continuous track has a plurality of apertures. Theapertures892 can be sized and shaped to fit onto one of a plurality ofprotrusions894 that can protrude from the drive andbogie wheels864 and868. Thus, theapertures892 can engage thedrive wheel864 so that when the drive wheel rotates the continuous track also rotates. Additionally, the plurality ofapertures892 and the plurality ofprotrusions894 can be sized and shaped to expel snow and ice from thecontinuous track860 as theprotrusions894 protrude into and engage theapertures892. Cleats or treads896 on the external side866 of thetrack860 can engage the ground and propel the trackedvehicle800 forward.

As illustrated inFIGS. 22-23 and26-27, each of the spaced apartmembers910 and920 of therear fork900 can also include atensioning member916 and926 respectively. Thetensioning members916 and926 can be coupled to the distal orback end914 and924 of the spaced apartarms910 and920 of therear fork900. Thetensioning members916 and926 can bias thebogie wheel868 to the spaced apart position with respect to thedrive wheel864. In this way, thetensioning members916 and926 can keep tension on thecontinuous track860 between thebogie wheel868 and thedrive wheel864.

Thetensioning members916 and924 can include a biasing device960 that can provide a resistive force against between the rear fork and the bogie wheel. As illustrated inFIGS. 26-27, the biasing device960 can be a spring, or a plurality ofsprings990 that push against the rear fork and the tensioning member. The tensioning members can be biased horizontally.

Referring again theFIGS. 22 and 23, the spaced apartmembers910 and920 of therear fork900 can be substantially horizontal from a predetermined rearward location918 and928 to the rear ordistal end914 and924. Advantageously, this horizontal portion of therear fork900 can restrict any vertical forces that may act on thebogie wheel868, such as from uneven terrain, from delivering or distributing a horizontal force component to the tensioning member960. In this way, horizontal forces which may loosen the tension on thecontinuous track860 may be minimized so that thetrack860 can maintain contact with the drive andbogie wheels864 and868. It will be appreciated that a horizontal force component that may push thebogie wheel868 toward thedrive wheel864 will loosen the tension in thecontinuous track860, thereby allowing thetrack860 to slip or momentarily disengage the drive and/or bogie wheels causing a jerky motion to the vehicle and thedrive assembly850. Moreover, sufficient slack may allow thecontinuous track860 to slip off the drive and/or bogie wheels entirely. Thus, thetensioning members916 and926 of the present invention operate to keep thetrack860 engaged with the drive and bogie wheels so thevehicle800 will properly operate in snow or muddy conditions.

Abias member876 can be operatively coupled between theframe834 and therear fork900. Thebias member876 can bias therear fork900 and thus the drive andbogie wheels864 and868 towards the ground. It will be appreciated that biasing the drive andbogie wheels864 and868 to the ground will maintain greater surface area contact between thecontinuous track860 and the ground. Thus, in use, the drive andbogie wheels864 and868 can pivot up and down with respect to theframe834 as the trackedvehicle800 moves over uneven terrain, but the drive andbogie wheels864 and868 can be biased to a downward position so as to maintain maximum surface area contact between thetrack860 and the ground.

The trackedvehicle800 can also have afront ski assembly526 similar in many respects to the front ski assembly illustrated inFIGS. 19-21 which has been described in detail above. Thus, the above description of thefront ski assembly526 applies also to the trackedvehicle800 of the present embodiment illustrated inFIGS. 22-23.

Additional figures of the trackedvehicle800 described inFIGS. 22-23 can be found in Appendix A which includes additional embodiments and enabling information and is incorporated by reference in its entirety for all purposes herein.

It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present invention while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts of the invention as set forth in the claims.

Claims (13)

1. A snow bike apparatus, comprising:

a) a frame having a seat;

b) a front steering post and a handle bar, attached to one another and pivotally coupled to the frame;

c) a drive assembly, coupled to the frame, including:

i) a gear, rotatably coupled to the frame; and

ii) a drive chain, movably disposed around the gear;

d) a rear fork, pivotally coupled to the frame, having a pair of spaced apart members pivoted at a front or proximal end to the frame extending upward to a biasing attachment and then rearward and downward to a drive wheel attachment and then rearward to a bogie wheel attachment;

e) a drive wheel, rotatably attachable to the rear fork, and operatively attachable to the drive chain;

e) a bogie wheel, located rearward of, and spaced apart from, the drive wheel and rotatably coupled to the rear fork;

f) a continuous track, movably disposed around the drive and bogie wheels; and

h) a bias member, operatively coupled between the frame and the rear fork, configured to bias the drive wheel and bogie wheel towards the ground.

2. An apparatus in accordance withclaim 1, wherein the spaced apart members of the rear fork have a smooth curvilinear profile between the front and back ends to reduce stress concentration points in the rear fork and to minimize transferring forces to the frame.

3. An apparatus in accordance withclaim 1, further comprising:

a tensioning member, coupled to the distal or back end of the rear fork, to bias the bogie wheel to the spaced apart position with respect to the drive wheel to keep tension on the continuous track between the bogie wheel and the drive wheel.

4. An apparatus in accordance withclaim 3, wherein the spaced apart members are substantially horizontal from a predetermined rearward location to the rear or distal end to restrict any vertical forces on the bogie wheel from delivering a horizontal force component to the tensioning member.

5. An apparatus in accordance withclaim 1, wherein the drive wheel and bogie wheel are pivotally and fixedly attached to the rear fork to allow the drive wheel and bogie wheel to rotate without displacing relative to one another.

6. An apparatus in accordance withclaim 1, further comprising:

a) a ski support, pivotally attached to the front steering post;

b) a ski shock absorber, pivotally attached between the front steering post and ski support, configured to absorb applied loads from the ski support and minimize the transfer of forces between the ski support and the front steering post; and

c) a ski, pivotally attached to the ski support.

7. An apparatus in accordance withclaim 6, wherein the front steering post, the ski support, and the ski shock absorber define a three bar linkage that positions the ski shock absorber to absorb loading from the ski support and minimize the transference of loads from the ski support to the front steering post.

8. An apparatus in accordance withclaim 1, further comprising a motor associated with the gear to rotate the gear and drive the drive chain.

9. An apparatus in accordance withclaim 1, further comprising pedals associated with the gear to rotate the gear and drive the drive chain.

10. An apparatus in accordance withclaim 1, wherein the continuous track includes a plurality of tread segments pivotally linked with one another to form a continuous flexible track disposed about the drive and bogie wheels.

11. An apparatus in accordance withclaim 10, wherein each of the plurality of tread segments has an aperture sized and shaped to fit onto one of a plurality of protrusions disposed on the drive wheel and configured to engage the drive wheel so that when the drive wheel rotates the continuous track rotates.

12. An apparatus in accordance withclaim 11, wherein the plurality of apertures and the plurality of protrusions are sized and shaped to expel snow and ice from the continuous track as the protrusions engage the apertures.

13. An apparatus in accordance withclaim 1, wherein the rear fork is pivotally attached to the frame at or substantially at the gear of the drive assembly.

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